w w ap eP m e tr .X w MARK SCHEME for the November 2004 question paper 7010 COMPUTER STUDIES 7010/01 Paper 1, maximum raw mark 100 This mark scheme is published as an aid to teachers and students, to indicate the requirements of the examination. It shows the basis on which Examiners were initially instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began. Any substantial changes to the mark scheme that arose from these discussions will be recorded in the published Report on the Examination. All Examiners are instructed that alternative correct answers and unexpected approaches in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills demonstrated. Mark schemes must be read in conjunction with the question papers and the Report on the Examination. • CIE will not enter into discussion or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the November 2004 question papers for most IGCSE and GCE Advanced Level syllabuses. om .c s er UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Ordinary Level November 2004 GCE O LEVEL MARK SCHEME MAXIMUM MARK: 100 SYLLABUS/COMPONENT: 7010/01 COMPUTER STUDIES Paper 1 Page 1 (1) (a) (b) (c) (d) (e) Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 Paper 1 MICR any two from: magnetic ink character (reader/recognition) E13B character set allows automatic data entry scanner/device/bank, special ink = 0 example: numbers on the bottom of a cheque, draw characters [2] batch processing any two from: processing does not start until all data collected reference to JCL no need for user interaction example: payroll system electricity/gas/water (etc.) billing cheque processing [2] modem any two from: modulator-demodulator converts digital/data to analogue (and vice versa)/converts binary into sound allows communication over telephone lines (NOT a converter, device) example: surf/connect to the net [2] virus any two from: program/software which replicates/copies itself damages files/corrupts files/corrupts boot sector corrupts memory stops computer working, stops proper functioning = 0 examples: worms, Trojan horse, time bomb, logic bomb [1 example only] [2] interrupt any two from: a signal/request generated by a device/program causes a break in the execution of a program/stops the program two devices=0 example: reference to printer [2] © University of Cambridge International Examinations 2005 Page 2 (2) (3) Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 Paper 1 Any three from: automatic re-ordering is possible easier stock taking/automatic stock taking easier to identify correct part fewer errors (in obtaining correct part, on input, etc.) need for fewer people in the stores easier to locate part/automate stores out of date parts can be automatically identified no need to remember prices (supermarkets)/no need to put price on goods faster data entry/no need to key in easier to do price changes prevents/reduces stealing shorter queues=0 less storage space used = 0 itemised receipts = 0 information held on the bar code = 0 (easier/faster = 0 unless qualified) (a) feasibility study 1 mark for both in correct order analysis } } } design } 1 mark implementation } } } 1 mark for both in correct order evaluation (b) any two from: systems flowchart/block diagram design data capture forms/input methods/user interface select/design appropriate hardware select/design appropriate software/write programs/algorithms design screen displays design reports/output design files/tables/records/validation rules design test plan/test strategy design (on its own) = 0 (NOT interviews, questionnaires, look at system etc.) © University of Cambridge International Examinations 2005 [3] [3] [2] Page 3 (4) (a) Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 any two from: data/images can be transferred/imported automatically/faster image can be manipulated/viewed straight away/no need to develop can store considerably more data/photos can store other info (apart from photo image) e.g. road conditions chips can be re-used more reliable, more robust, safer = 0 Paper 1 [2] (b) any two from: calculate/sense/collect (or record) speed of vehicle compare speed of vehicle with stored value(s)/decide whether photograph should be taken check on value of light intensity/adjust focal length/focus image/adjust shutter speed/set exposure - (**) [2] (c) any two from: log time/date/speed/road conditions operate “flash” operate shutter store image check on value of light intensity/adjust focal length/focus image/adjust shutter speed/set exposure – (**) [2] (** - only award this mark once either in part (b) OR part (c)) (5) (6) Any three from: sound (voice) output/speech synthesiser speech (voice) input/recognition/microphones large characters on the screen braille keyboards/touch screens/touch pads/larger keys/other special keyboards use of bright colours to improve visibility scanners to input information and output speech printers which give output in Braille touch typing = 0 multimedia, games, animation=0 (unless qualified wrt question) [3] (a) (b) any two from stores data/information being sent to printer temporarily compensates for difference in speed of CPU and printer allows CPU to carry out other tasks whilst printer is printing [2] any one from reduces the number of data transfers to the printer more efficient use of the CPU larger files can be sent to the printer [1] © University of Cambridge International Examinations 2005 Page 4 (7) (a) (b) (c) (8) (a) (b) (9) Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 Paper 1 (B2 – C2) * D2 < - 1 mark -><- 1 mark -> [2] any two from: highlight E2 and select copy paste in cells E3:E5 (or equivalent using, for example, drag and drop formula) [2] any two from: use of graphs description of how graph used showing data in additional columns of the spreadsheet use of other formulae such as, for example, (B3-F3)/C3 to estimate days number of days column (on its own) = 0 [2] any two from: illegal copying of software/software piracy sending viruses hacking into systems/altering information illegally fraud/improper transfer of funds/data theft sabotage/malicious damage mis-use of data = 0 blackmailing = 0 (unless qualified) [2] any three from: data encryption use of passwords/access codes/PIN software security built into system/use of firewalls anti-virus software log users/computer use software security built into system use call back facility for incoming information take/check references of potential staff divide jobs between several people/supervise staff physical locks use of laws/back ups = 0 [3] any three from: file management input/output control spooling memory management multi-tasking/JCL multi-programming handling interrupts error reporting security interface with user/use of WIMP load/run programs processor management [3] © University of Cambridge International Examinations 2005 Page 5 (10) (a) (b) Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 Paper 1 any two advantages to customer from: can easily search for the cheapest offer don’t need to leave home/more time to choose can shop any time (24/7) - ** save on travelling costs more choice available can do shopping by setting up a file no need to carry cash, can use credit card = 0 [2] any two advantages to shop managers from: potentially greater number of customers/wider audience/hyperlinks increase in sales more goods can be made available can sell at any time - ** cheaper – no leaflets, etc. can reduce number of shops on the high street/no need for shops can employ fewer staff no need to be in the shop/can run business from home less queues, better presentation = 0 [2] (** only accept this answer in (a) OR (b)) (c) any three disadvantages from: no interaction with people fear of rogue companies/might not receive goods cannot see the goods first not everyone has a computer not everyone has a credit card need for further technological advances fear of hacking/card fraud delay in delivery of goods, high transport costs = 0 [3] (11) any three from: faster/easier access direct/random access easier to update disks more robust reference to memory size = 0 [3] (12) Output values: 9 (or b) 8 (or c) 4 (or b) Accept only one answer per line [3] (13) (a) (b) length check – to ensure up to 30 letters of alphabet only character check – to ensure name doesn’t contain numeric characters [2] range check – to ensure marks are within correct boundaries (e.g. between 0 and 100) length check – to ensure no more than 3 digits are input type/character check – to ensure number is numeric [2] (NOTE: in both above parts, presence checks and check digits = 0) © University of Cambridge International Examinations 2005 Page 6 (14) (a) Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 any two from: no need for the company to transport staff around/safer for employees saves time since less travelling saves travelling costs/saves accommodation costs no need to leave home/office easier for several delegates to take part simultaneously body language = 0, faster/saves time (on its own) = 0 Paper 1 [2] (b) easier to send copies of same document to several people no need for stamps electronic copy held, but with phone call no copy held/auto confirmation easier to send files/spreadsheets/databases can read at any time cheaper than normal post service faster than normal post service time differences around the world will not cause a problem faster, cheaper (on its own) = 0 reference to attachments = 0 (unless qualified e.g. it is easier to send files as attachments …….) [2] (c) any two from: people print out copies for meetings and then destroy them afterwards….. …. but if needed again, print out another copy (both lines = 1 mark) some people find it difficult reading large amounts of text on the screen people often e-mail colleagues rather than use the phone who then print out the document [2] (15) (a) any three steps from: gather information from experts in the field create/design knowledge base input data into knowledge base design/create rule base create/design interrogation technique/questions and answers/inference engine create/design display of results/user interface (databases = 0 marks) [3] (b) (c) any two from: no need for an expert to be present can act as a prompt to an expert can deal with complex situations much faster than humans could be used in hazardous areas (e.g. oil prospecting) less likely to make an error more consistent in diagnosing faults/more accurate (cheaper = 0) [2] any one from: medical diagnosis mineral prospecting chess tax/financial calculations weather forecasting fault diagnostics criminology/forensic science career choices (names of expert systems = 0) [1] © University of Cambridge International Examinations 2005 Page 7 (16) (a) (b) Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 Paper 1 any two from: draw geometrical shapes/colour fill zoom/rotate/scale/crop/skew three dimensions/layers use of simulations can do calculations e.g. costing of components, stress, volumes link to CAM store/retrieve drawings/images library of components/templates labelling/adding text [2] graph plotter – to produce high quality drawings/plans in various paper sizes (reference to graphs = 0, prints out = 0) graphics tablet – to provide interface for drawing on the screen/links with the light pen light pen – to make alterations on the screen to the drawings/write directly on the screen/select commands trackerball – draw designs/select options from menu © University of Cambridge International Examinations 2005 [4] Page 8 (17) (a) Mark Scheme GCE O LEVEL – NOVEMBER 2004 (i) Syllabus 7010 any one example of numeric field (1 mark for name of field + description, 1 mark for field length) name of field description field length ENGSIZE NUMDOOR FUELCON PRICE ODOMETER engine capacity (litres) number of doors economy of vehicle cost of vehicle recorded distance (km or miles) 4 1 3 6 7 (ii) Paper 1 any one example of text field name of field COLOUR MODEL PREVOWN OPTION description field length colour of vehicle make and model of vehicle details of previous owner list of extras on vehicle 20 20 50 30 [4] (b) any one example for each operation: amend information is incorrect price of vehicle needs to be changed (e.g. sales) change of colour delete (record deleted) vehicle sold vehicle scrapped insert (info into a field) new vehicle arrived more information about current vehicle becomes known [3] © University of Cambridge International Examinations 2005 Page 9 (18) (a) (b) (c) (d) Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 Paper 1 any two from: pressure sensor temperature sensor (thermometer) radiation sensor/detector escaping gas sensor/detector [2] ADC (analogue to digital converter) DAC, modem = 0 [1] any three points from: output affects the input data from sensors sent to computer data compared with stored values computer sends information to valves (etc.) to control gases reference to loop in control program reference to heaters/coolers = 0 [3] any two from: can monitor/control process remotely/at a distance safer way of operation/less danger to humans computer is faster at diagnosis/taking necessary action ability to automatically analyse data/produce graphs less need for human intervention/24 hour monitoring/workers get tired more accurate control [2] © University of Cambridge International Examinations 2005 Page 10 Mark Scheme GCE O LEVEL – NOVEMBER 2004 Syllabus 7010 Paper 1 (19) Sample answer: repeat input start_point } input end_point } input number } cost = abs(start_point - end_point) * number * 2 } 2 marks if number >= 3 then cost = cost – (cost/10) } 1 mark input money } 1 mark change = money – cost } 1 mark for x = 1 to number } print ticket 1 mark } 1 mark next x } 1 mark output change } until no more customers } 1 mark General marking points: (initialisation = 0) inputs – 1 mark calculate how many stations to charge for – 1 mark formula/if statement to calculate cost for ticket/no discount - 1 mark formula/if statement to calculate discount where appropriate - 1 mark input money - 1 mark formula to calculate change - 1 mark loop to control number of tickets to be printed - 1 mark print ticket/output change - 1 mark overall loop control - 1 mark [6] © University of Cambridge International Examinations 2005